Epoxide hydrolases (EHs, EC 3.3.2.3) catalyze the hydrolysis of epoxides or arene oxides to their corresponding diols by the addition of water (see, Oesch, F., et al., Xenobiotica 1973, 3, 305-340). EHs play an important role in the metabolism of a variety of compounds including hormones, chemotherapeutic drugs, carcinogens, environmental pollutants, mycotoxins, and other harmful foreign compounds.
There are two well-studied EHs, microsomal epoxide hydrolase (mEH) and soluble epoxide hydrolase (sEH). These enzymes are very distantly related, have different subcellular localization, and have different but partially overlapping substrate selectivities. The soluble and microsomal EH forms are known to complement each other in detoxifying a wide array of mutagenic, toxic, and carcinogenic xenobiotic epoxides (see, Hammock, B. D., et al., COMPREHENSIVE TOXICOLOGY. Oxford: Pergamon Press 1977, 283-305 and Fretland, A. J., et al., Chem. Biol. Intereract 2000, 129, 41-59).
The sEH is also involved in the metabolism of arachidonic acid (see, Zeldin, D. C., et al., J. Biol. Chem. 1993, 268, 6402-6407), linoleic (see, Moghaddam, M. F., et al., Nat. Med. 1997, 3, 562-567) acid, and other lipid epoxides, some of which are endogenous chemical mediators (see, Carroll, M. A., et al., Thorax 2000, 55, S13-16). Epoxides of arachidonic acid (epoxyeicosatrienoic acids or EETs) are known effectors of blood pressure (see, Capdevila, J. H., et al., J. Lipid. Res. 2000, 41, 163-181), and modulators of vascular permeability (see, Oltman, C. L., et al., Circ Res. 1998, 83, 932-939). The vasodilatory properties of EETs are associated with an increased open-state probability of calcium-activated potassium channels leading to hyperpolarization of the vascular smooth muscle (see Fisslthaler, B., et al., Nature 1999, 401, 493-497). Hydrolysis of the epoxides by sEH diminishes this activity (see, Capdevila, J. H., et al., J. Lipid. Res. 2000, 41, 163-181). sEH hydrolysis of EETs also regulates their incorporation into coronary endothelial phospholipids, suggesting a regulation of endothelial function by sEH (see, Weintraub, N. L., et al., Am. J. Physiol. 1992, 277, H2098-2108). It has recently been shown that treatment of spontaneous hypertensive rats (SHRs) with selective sEH inhibitors significantly reduces their blood pressure (see, Yu, Z., et al., Circ. Res. 2000, 87, 992-998). In addition, male knockout sEH mice have significantly lower blood pressure than wild-type mice (see Sinal, C. J., et al., J. Biol. Chem. 2000, 275, 40504-405010), further supporting the role of sEH in blood pressure regulation.
The EETs have also demonstrated anti-inflammatory properties in endothelial cells (see, Node, K., et al., Science 1999, 285, 1276-1279 and Campbell, W. B. Trends Pharmacol. Sci. 2000, 21, 125-127). In contrast, diols derived from epoxy-linoleate (leukotoxin) perturb membrane permeability and calcium homeostasis (see, Moghaddam, M. F., et al., Nat. Med. 1997, 3, 562-567), which results in inflammation that is modulated by nitric oxide synthase and endothelin-1 (see, Ishizaki, T., et al., Am J. Physiol. 1995, 269, L65-70 and Ishizaki, T., et al., J. Appl Physiol. 1995, 79, 1106-1611). Micromolar concentrations of leukotoxin reported in association with inflammation and hypoxia (see, Dudda, A., et al., Chem. Phys. Lipids 1996, 82, 39-51), depress mitochondrial respiration in vitro (see, Sakai, T., et al., Am. J. Physiol. 1995, 269, L326-331), and cause mammalian cardiopulmonary toxicity in vivo (see, Ishizaki, T., et al., Am. J. Physiol. 1995, 269, L65-70; Fukushima, A., et al., Cardiovasc. Res. 1988, 22, 213-218; and Ishizaki, T., et al., Am. J. Physiol. 1995, 268, L123-128). Leukotoxin toxicity presents symptoms suggestive of multiple organ failure and acute respiratory distress syndrome (ARDS) (see, Ozawa, T. et al., Am. Rev. Respir. Dis. 1988, 137, 535-540). In both cellular and organismal models, leukotoxin-mediated toxicity is dependent upon epoxide hydrolysis (see, Moghaddam, M. F., et al., Nat. Med. 1997, 3, 562-567; Morisseau, C., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 8849-8854; and Zheng, J., et al., Am. J. Respir. Cell Mol. Biol. 2001, 25, 434-438), suggesting a role for sEH in the regulation of inflammation. The bioactivity of these epoxy-fatty acids suggests that inhibition of vicinal-dihydroxy-lipid biosynthesis may have therapeutic value, making sEH a promising pharmacological target.
Recently, 1,3-disubstituted ureas, carbamates, and amides have been reported as new potent and stable inhibitors of sEH (FIG. 1). See, U.S. Pat. No. 6,150,415. Compounds 192 and 686 are representative structures for this type of inhibitors (FIG. 1). These compounds are competitive tight-binding inhibitors with nanomolar KI values that interact stoichiometrically with purified recombinant sEH (see, Morisseau, C., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 8849-8854). Based on the X-ray crystal structure, the urea inhibitors were shown to establish hydrogen bonds and to form salt bridges between the urea function of the inhibitor and residues of the sEH active site, mimicking features encountered in the reaction coordinate of epoxide ring opening by this enzyme (see, Argiriadi, M. A., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 10637-10642 and Argiriadi, M. A., et al., J. Biol. Chem. 2000, 275, 15265-15270). These inhibitors efficiently reduced epoxide hydrolysis in several in vitro and in vivo models (see, Yu, Z., et al., Circ. Res. 2000, 87, 992-998; Morisseau, C., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 8849-8854; and Newman, J. W., et al., Environ. Health Perspect. 2001, 109, 61-66). Despite the activity associated with these inhibitors, there exists a need for compounds possessing similar or increased activities, with improved solubility to facilitate formulation and delivery.
Surprisingly, the present invention provides such compounds along with methods for their use and compositions that contain them.